The present invention relates generally to a system which informs a traveller of the correct local time and city location based on an analysis of radiowave frequencies.
In order to keep abreast of the correct time, travellers who cross time zones in their travels must manually reset the time displayed on their timepieces in accordance with the time zone they have reached. This is an inconvenience not only because the traveller must remember to reset the timepiece but also because the correct time in the new time zone may not be evident to the traveller. Failing to have the correct local time may lead to missed appointments, missed transit connections, etc. Even in cases where travellers travel in the same time zone, they may mistakenly believe they crossed a time zone and incorrectly reset their timepieces.
The broadcast radiowave frequencies from radio stations at known city locations are published, e.g., in the World Radio TV Handbook by BillBoard A.G. A traveller who leaves the vicinity of a first city to enter the vicinity of a second city, will then be within the broadcast range of radio stations in that second city and possibly no longer within the broadcast range of radio stations in the first city. Even if the cities are close, so that radiowave frequencies from the first city are still received, they will be weaker than those from the second city.
It would therefore be desirable to devise an entirely passive system which by using the foregoing characteristics automatically informs a traveller of the correct time in a given time zone and of the city at which the traveller has arrived and additional local information.